Key Financial Data Of Reporting Company
| Concept | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | As at 2025-03-31 | As at 2025-03-31 | 2024-04-01 to 2025-03-31 | 2023-04-01 to 2024-03-31 | 2023-04-01 to 2024-03-31 | As at 2024-03-31 | As at 2024-03-31 | 2022-04-01 to 2023-03-31 | As at 2023-03-31 | As at 2023-03-31 | 2022-04-01 to 2023-03-31 | 2021-04-01 to 2022-03-31 | 2021-04-01 to 2022-03-31 | As at 2022-03-31 | As at 2022-03-31 | As at 2021-03-31 | 2020-04-01 to 2021-03-31 | 2020-04-01 to 2021-03-31 | As at 2021-03-31 | 
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Key financial data of reporting company | |||||||||||||||||||||
| Business results of reporting company | |||||||||||||||||||||
| Net sales | — | 
                                                43,971,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                40,948,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                37,320,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                30,793,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                36,561,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Operating revenue | — | — | — | — | 
                                                25,737,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                1,774,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                924,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                1,279,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,673,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Ordinary profit (loss) | — | 
                                                3,404,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,096,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                641,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                3,406,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                194,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                2,386,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                211,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                369,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                491,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                2,269,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Profit (loss) | — | — | — | — | 
                                                6,932,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                630,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                165,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                290,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,421,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
| Share capital | — | — | 
                                                10,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                10,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                10,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                10,836,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total number of issued shares | — | — | 
                                                6,244,962
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,244,962
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | 
                                                6,244,962
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | — | — | 
                                                6,244,962
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | — | — | — | 
                                                6,244,962
                                                
                                                    
                                                        xbrli:shares
                                                    
                                                
                                             | 
| Net assets | 
                                                30,764,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                26,875,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                28,368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,662,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                19,288,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                24,894,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                23,497,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                19,298,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                23,033,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                19,183,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Total assets | 
                                                45,203,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                35,996,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                41,473,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,950,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                22,944,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                41,777,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                36,845,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                22,895,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
                                                36,483,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | 
                                                22,242,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | 
| Net assets per share | 
                                                5,314.33
                                                
                                             | — | 
                                                4,642.45
                                                
                                             | — | — | — | — | 
                                                4,874.29
                                                
                                             | 
                                                3,378.39
                                                
                                             | — | 
                                                3,303.46
                                                
                                             | 
                                                4,263.55
                                                
                                             | — | — | — | 
                                                4,024.24
                                                
                                             | 
                                                3,305.09
                                                
                                             | 
                                                3,909.56
                                                
                                             | — | — | 
                                                3,284.90
                                                
                                             | 
| Dividend paid per share | — | — | — | — | 
                                                165.00
                                                
                                             | 
                                                135.00
                                                
                                             | — | — | — | 
                                                35.00
                                                
                                             | — | — | — | 
                                                30.00
                                                
                                             | — | — | — | — | 
                                                30.00
                                                
                                             | — | — | 
| Interim dividend paid per share | — | — | — | — |  |  | — | — | — |  | — | — | — |  | — | — | — | — |  | — | — | 
| Basic earnings (loss) per share | — | 
                                                603.48
                                                
                                             | — | — | 
                                                1,194.63
                                                
                                             | 
                                                108.08
                                                
                                             | 
                                                479.87
                                                
                                             | — | — | 
                                                28.42
                                                
                                             | — | — | 
                                                103.07
                                                
                                             | 
                                                49.75
                                                
                                             | 
                                                194.74
                                                
                                             | — | — | — | 
                                                -243.45
                                                
                                             | 
                                                -37.31
                                                
                                             | — | 
| Diluted earnings per share | — |  | — | — |  |  |  | — | — |  | — | — |  |  |  | — | — | — |  |  | — | 
| Equity-to-asset ratio | 
                                                0.681
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.747
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                0.684
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.857
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                0.841
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.596
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.638
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.843
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.626
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.863
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Rate of return on equity | — | 
                                                0.118
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.298
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.032
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.105
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.009
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                0.025
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.015
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                0.049
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -0.001
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -0.010
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Price-earnings ratio | — | 
                                                5.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                2.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                28.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                6.4
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                65.7
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                18.1
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                30.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                7.9
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                -6.6
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                -43.0
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
| Payout ratio | — | — | — | — | 
                                                0.138
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1.249
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.232
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                0.603
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | 
                                                
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
| Net cash provided by (used in) operating activities | — | 
                                                3,267,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                3,737,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1,731,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                -1,075,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                1,903,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) investing activities | — | 
                                                -2,813,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -569,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                -666,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                214,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,087,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Net cash provided by (used in) financing activities | — | 
                                                477,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -1,967,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | 
                                                74,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                42,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | 
                                                -679,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
| Cash and cash equivalents | 
                                                10,291,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                9,368,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                8,134,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
                                                6,993,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | 
                                                7,808,000,000
                                                
                                                    
                                                        JPY
                                                    
                                                
                                             | — | — | — | 
| Number of employees | 
                                                1,207
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                522
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                288
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1,078
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                47
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                35
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,098
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1,108
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                37
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
                                                1,125
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | 
                                                30
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Average number of temporary employees | 
                                                148
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | — | 
                                                116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                116
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                112
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                104
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
| Total shareholder return | — | — | 
                                                2.300
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2.197
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.298
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.056
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.081
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | 
| Total return on share price index | — | — | 
                                                2.134
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                2.168
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | 
                                                1.534
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | — | — | 
                                                1.450
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             | — | — | — | 
                                                1.421
                                                
                                                    
                                                        xbrli:pure
                                                    
                                                
                                             |